Large-scale offshore grid infrastructure

In the last years the initiatives promoting a large-scale offshore grid infrastructure in the North Sea received a growing political support by European institutions.

Pre-feasibility studies already demonstrated technical and economic benefits of such an offshore grid for the connection of offshore wind farms, the electrification of oil rigs and the establishment of a pan-European electricity market.

The realization of an offshore grid is already theoretically feasible since the major building blocks necessary for its construction are commercially available.

Challenge

The operation of such a complex infrastructure represents a major knowledge need for the industry since no similar configurations are in operation today and standard practices valid for conventional AC transmission grids cannot be directly transposed.

In particular, it is still a challenge to ensure reliable operation and a selective protection. Indeed, the design of the protections is limited by the lack of commercial DC breakers with suitable specifications. In addition, the large penetration in an electrical system of power converters can produce unexpected interactions with potential impact on the overall reliability.